1. Field of the Invention
The present invention relates to a formed body comprised of one or more aromatic polyesters derived from diphenols and halides of phthalic acid.
2. Description of the Prior Art
Aromatic polyesters of this kind are known e.g. from the European patent Specifications Nos. 64971 and 64972 and the corresponding U.S. Pat. Nos. 4,387,209 and 4,388,454, the disclosures of which are hereby incorporated by reference. As disclosed in these prior art specifications, the aromatic polyesters are produced in the form of films obtained by means of a casting process from the polyester solution. The polyester described in European Patent Specification No. 64972 and its corresponding U.S. Pat. No. 4,388,454 is a polyester based on 1,1-bis(4-hydroxyphenyl)-1-phenylethane, which is not easy to process by extrusion or injection molding due to its high process temperature in the range of 330.degree.-400.degree. C. The polyester based on 9,9-bis(4-hydroxyphenyl)fluorene as described in European Patent Specification No. 64971 and its corresponding U.S. Pat. No. 4,387,209 has no melting range at all. It begins to decompose thermally at a temperature of about 400.degree. C.